A KEY MILL

Abstract: A key mill in which one or more carriages (10, 14, 15) are mounted to a frame (2) with means (50) to move the carriage(s) relative to the frame in an axial direction (X) and with means (48) to move the carriage(s) transverse (Y) to the axial direction towards a notch forming means (26, 96) mounted to the frame. A milling head with a milling tool (28) is movable in a further direction (Z) substantially at a right angle to the axial direction (X) and at an angle to the transverse direction (Y). An indicator (62, 58) is provided for indicating the axial and transverse movement of the carriage and a further indicator (74) is provided for indicating movement of the milling tool in the further direction (Z). At least one clamp (19, 22, 24) is provided for clamping a key blank to the carriage(s) so that a key blank held in a clamp (19, 22, 24) may be machined according to a predetermined shape indicated by the indicating means or else duplicated from a master key clamped to the carriage. The machine is designed to provide easy and accurate duplication of keys and to enable a variety of keys to be cut in particular where vertical milling is required.

Description: A Kev Mil l The present invention relates to a key mill for cutting keys from blanks particularly for duplicating from an existing key or from a manufacturers specification. Key mills for duplicating keys from blanks are well known. One such mill is shown and described in US Patent No. 4,117,763 (Uyeda) . In the Uyeda mill a key blank is clamped into a carriage which can be moved in the axial direction of the blank and transverse to that direction towards a cutting or grinding wheel rotating in the axial direction so that spaced notches may be cut in the blank. In order to ensure the notches are in the correct place a master key or key to be duplicated is clamped into the same carriage and a follower engaging with the master is used to guide the operator to move the carriage in the axial and transverse directions. To ensure accuracy when copying from the key to be duplicated the axial and transverse movements of the carriage are indicated by two dial pointers which sweep over a table on which one of several indexing cards is located. The indexing card has indications for the axial movement or notch spacing and the transverse movement or notch depth. This arrangement is quite satisfactory for flat keys but is unsuitable for keys in which the notches are only partly cut through the blank that is to say where a vertical cut is required. A key mill according to the invention comprises a frame, at least one carriage including at least one clamp for clamping at least a key blank to the carriage, means to move the carriage relative to the frame in an axial direction, means to move the carriage transverse to the axial direction towards a key notch forming means mounted to the frame, a milling head arranged to carry a milling tool and to move the tool in a further direction at substantially a right angle to the axial direction and at an angle to the transverse direction, indicator means for indicating the axial and transverse movement of the carriage and further indicator means for indicating movement of the milling tool in the further direction. Preferably the carriage has a first said clamp at a first station adjacent the notch forming means and a second said clamp at a second station adjacent the milling head. In a preferred embodiment there are duplicate clamps at each station and means for following the shape of a key at either duplicate clamp. An embodiment of the invention will now be described with reference to the accompanying drawings in which:- Figure 1 is a perspective view of a key mill according to the invention, Figure 2 is a cross-section of a vertical milling head follower for the mill of Figure 1, and Figure 3 is a cross-section of a right hand card holder indexed needle mechanism for the mill of Figure 1 viewed from above, Figure 4 is a cross section of part of the mechanism of Fig. 3 looking horizontally from the left of Fig. 1, Figure 5 is a cross section of the mechanism of Fig. 3 seen from the right of Fig. 1, Figure 6 is a cross section of a left hand card holder seen from the right of Fig. 1, Figure 7 is a plan view of the left hand holder of Fig. 6, Figure 8 is a key type for horizontal milling, Figure 9 is a key type for vertical milling in the mill of Figure 1, and Figure 10 is a diagrammatic plan view of the mill of Figure 1. The key mill shown in the drawings comprises a frame 2 on which is mounted by means of bearings 4, 5 and two further bearings 7 and 9 (see Fig. 3) in frame part 6 a mainshaft 8 axially aligned in the X direction. A first carriage 10 at a first or first horizontal milling station 12 is fixedly mounted at a central point on the shaft, a second carriage 14 at a second or vertical milling station 16 is fixedly mounted at an axially spaced position on the shaft and a third carriage 15 is at a third or auxiliary horizontal milling station 17. A first key duplicate clamp 18 and a second key duplicate clamp 20 are provided on the top of respective carriages 10 and 14. A first key blank clamp 22 and a second key blank clamp 24 are also provided on the top of respective carriages 10 and 14 in locations axially spaced from duplicate clamps 18 and 20. A third key blank clamp 19 is provided on top of third carriage 15. Clamp 19 is removably and reversibly mounted on carriage 15 and includes a key holder 91 which is slidably adjustable in the X direction on slide way 93 and which is clamped in the desired position by clamp knob 94. A blank key K3 in holder 91 may also be turned about a horizontal axis by indexed wheel 92, the key blank K3 being held in a key engaging rotatable bearing 95 within holder 91. A slot 21 aligned in the X direction on top of each clamp 20, 24 is provided to receive a key K4 to be duplicated and a key blank Kl respectively. Each slot 21 has a transverse slot 23 in the Y direction into which a removable locating gate 25 is fitted. Pivotal movement of shaft 8 either by means of a handle 31 on shaft 8 or by transverse feed handle 48 causes all the carriages to move transversely towards a first horizontal milling cutter 26 a second horizontal milling cutter 96, and vertical milling tool 28. Shaft 8 is enabled to move in its bearings in its axial direction X so as to move the carriages axially by means of an axial feed handle 50 which turns feed screw 52 (see Fig. 3) to move plate 51 coupled to shaft 8. A milling head 30 is mounted to bracket 32 for vertical movement so that the milling tool 28 can move in a direction towards a key blank Kl in clamp 24 in a direction Z at right angles to the axial direction X of shaft 8 and substantially at right angles to the median transverse tangential direction of movement Y of the carriages. Means for following the shape of a master or duplicate key K4 clamped in clamps 18 and 20 are respectively followers 34 and 36. Vertical follower 36 shown in Figure 2 is similar to horizontally mounted transverse follower 34 and comprises a follower tip 38 indexed toward the master key K4 (clamped in clamp 20) by a screw threaded shaft 40. Handle 42 is provided to raise the tip 38 from the master key to a disengaged position. Shaft 40 is locked by a lock nut 44 rotatable by handle 46. Similarly nut 48 is provided to move the follower 34 transversely towards or away from a master key (not shown) clamped in clamp 18. The follower 34 is indexed toward the master key by means of a thread on the follower shaft (not shown) and is locked by screw 49. Clamps 18, 20, 22 and 24 can be rotated through 180° by slackening lock knobs 27 to clamp different shaped master keys and key blanks. Each carriage 10, 14 and 15 is locked to shaft 8 by a clamping screw 11 and nut 13 (shown in Fig. 5) so that the carriages can be adjusted relative to each other and to the respective cutters and card index needles. In order to move the clamps on carriages 10, 14 and 15 transversely when using an index card to guide the carriages, the transverse feed handle 48 acts on the shaft 49 which is fixed to carriage 10 which in turn is fixed to shaft 8 to which carriage 14 is fixed. A spring 53 (see Fig. 5) is provided to urge the carriages back onto handle 48. The transverse movement of the clamps is in reality a pivotal movement about the axis of shaft 8, however the radial distance from the clamping position to the axis of the shaft 8 is sufficiently great as not to make any significant cutting error when milling transversely or axially. Indication of the depth of cut in the transverse direction Y is by means of a rod 54 aligned in the X direction and fixed at one end to carriage 10. Rod 54 abuts at its other end on a sprung rod 56 aligned and movable in the Y direction in block 57. Rod 56 acts through gearing 65 on indicator dial needle 58. Rod 56 can be disengaged from rod 54 by means of a stop 59 which can be engaged in rod 56 when rod 56 is at the rear end of its stroke away from handle 48. This enables the shaft 8 to be pivoted freely against spring 53 to move the carriages in the Y direction by means of handle 31 on shaft 8. Control by handle 31 enables the cutting action either by tool 28 or tool 26 to be controlled by pressing a master key in clamp 20 or clamp 18 onto followers 36 or 34 respectively. Correct axial location of the master key relative the key blank is achieved by locating the master and blank against gates 25 when milling vertically. Axial movement of the carriage is by means of axial feed handle 50 turning feed screw 52. The axial movement is transmitted through rack and pinion gearing 60 to dial needle 62. A card 64 has the necessary indications for depth and spacing positions and is removably held in card holder 82. Vertical movement of milling tool 28 mounted on shaft 73 carried in bearings 75 is controlled by rotation of indexing handle 70 which rotates through a cog wheel 71 an externally toothed cylindrical housing 72 threaded at 77. Vertical movement is indicated by index needle 74 which swings over a dial marked on an index card 170. Tool 28 is driven by pulley 76 in turn driven by a first motor 150 which drives drive pulley 78. Housing 72 is grooved at 75 round its lower part which is engaged by roller pawl 79. Pawl 79 moves up and down with pawl shaft 79' as housing 72 is raised and lowered by rotating in threaded bearing 77'. Pawl shaft 79' then transmits this movement to needle 74 via crank plate 11 and rack and pinion drive 80. Tool 26 in the horizontal milling section is driven through pulleys 179 and 180 by a second motor 152. A spring detent 81 locks the shaft (not shown) on which cutter tool 26 is mounted so as to enable cutter 26 to be removed from a threaded end of that shaft. A wire brush 154 is mounted on the drive shaft 156 of motor 152. Operation Depending on the type of key to be cut the appropriate key blank K2, Kl is clamped in clamp 22 or 24 to cut a first key type 100 shown in Fig. 4 which has notches 101 right through the blade 103 or respectively second key type 102 shown in Fig. 5 which has recesses 105 cut perhaps only a third through the thickness of the blade 106 leaving uncut portions 107. That is the first key type blank is fitted into clamp 22 and the second key type blank is fitted into clamp 24 with its tip 109 abutting on gate 25 fitted into slot 23. After clamp knob 27 is tightened gate 25 is removed to allow the tool 28 free passage along the length of the clamp. In a first cutting method where a master key is not used the vertical depth to be cut in the Z direction by tool 28 is set by aligning needle 74 on an indication on index card 170 by means of handle 70 from the key manufacturers specification. The specification also specifies a particular range of spacing of recesses 105 in the axial or X direction and a range of depths from edge 111 of key 102 in the Y direction. These are indicated on index card 64 which is fitted to card holder 82. Each key has specific X direction locations and Y direction depths taken from a table. The vertical mill motor 150 is switched on. A first cut is made by the tool 28 at the set Z direction depth and at an axial or X direction location set by handle 50 by means of needle 62 against an indication on card 64 and for a Y direction depth from the equivalent of edge ill on a blank as read off on an indication on card 64 as indicated by needle 58. The individual Z and Y direction settings are obtained from a manufacturers specification for each key. Subsequent cuts are made in the same way. In a second cutting method for keys of type 102, the master key which may be a duplicate of the master key is clamped into clamp 20 using gate 25 to locate the master in the correct axial or X direction and then removing the gate. A blank is similarly clamped in clamp 24 using gate 25. Handle 48 is disengaged by locking rod in its near position by stop 59 and the recesses 105 followed by following 36 under pressure from handle 31 and by axial movement in the X direction by turning handle 50. In a third cutting method where a duplicate of key 100 is to be made without using a master key the blank is clamped in clamp 22 by handle 22'. The appropriate index card 64 is fitted into card holder 82. The motor 80 is switched on and cuts made in the blank according to the particular key specification by cutter 78 adjusting handles 48 and 50 as necessary. In a fourth cutting method where a master key of the 100 type is present, the master key is clamped in clamp 18 and a blank in clamp 22. Follower 34 is adjusted and handles 31 and 50 manipulated with the motor 152 switched on so that the shape of the master key is copied onto the blank. In a fifth cutting method a key blank K3 is inserted into bearing 95 in holder 91 and the third method is followed. Where necessary the blank K3 is turned about its horizontal axis by indexed wheel 92. It will be appreciated that the carriages 10, 14 and 15 although separate are effectively a single carriage being coupled by shaft 8 and indeed could in theory be a single component; however, five clamps would still be needed for the embodiment described. Whilst two motors are provided a single motor could drive both cutters; however, it is cheaper to provided two motors avoiding thereby the cost of gearing required for a single motor.

Claims: C L A I M S 1. A key mill comprising a frame, at least one carriage including at least one clamp for clamping at least a key blank to the carriage, means to move the carriage relative to the frame in an axial direction, means to move the carriage transverse to the axial direction towards a key notch forming means mounted to the frame, a milling head arranged to carry a milling tool and to move the tool in a further direction at substantially a right angle to the axial direction and at an angle to the transverse direction, indicator means for indicating the axial and transverse movement of the carriage and further indicator means for indicating movement of the milling tool in the further direction. 2. A key mill according to claim 1 wherein the carriage has a first said clamp at a first station adjacent the milling head and a second said clamp at a second station adjacent the milling head. 3. A key mill according to claim 2 wherein there are duplicate clamps at each station. 4. A key mill according to claim 2 or 3 wherein there are means for following the shape of a key at each station. 5. A key mill according to any one of claims 1 to 4 wherein at least one clamp has a key blank receiving groove axially aligned with the said axial direction and a removable gate means for defining an end of the groove. 6. A key mill according to any one of claims 1 to 5 wherein the indicator means for indicating the axial and transverse movement of the carriage comprises an index card receiving means, a first pointer and a second pointer coupled to the carriage arranged to indicate the axial and transverse movement in relation to an index car on the receiving means. 7. A key mill according to any one of claims 1 to 6 wherein the further indicator means comprises a dial coupled to the milling head which is rotatably adjustable to move in the further direction. 8. A key mill according to claim 2 wherein a third clamp is provided at a third station at which a further milling tool is provided said further milling tool being rotatable about an axis parallel to the axial direction. 9. A key mill according to any one of claims 1 to 8 wherein the carriage or carriages is or are pivotally mounted about an axis in the axial direction. 10. A key mill according to claim 9 wherein the carriage or carriages are mounted on a shaft having a handle mounted thereto for manual movement of the carriage or carriages in the transverse direction. 11. A key mill according to any one of claims 1 to 10 wherein a depthing handle is provided as the means to move the carriage or carriages in the transverse direction, the depthing handle being arranged to bear on the carriage or carriages and wherein means are provided to disengage the action of the depthing handle on the carriage or carriages. 12. A key mill substantially as described with reference to the accompanying drawings.

Inventors: CLEMENT DAVID ALAN, MCMURRAY ALAN, CLEMENT, DAVID, ALAN, MCMURRAY, ALAN
Applicants: AUTOKEY UK LTD, CLEMENT DAVID ALAN, MCMURRAY ALAN, AUTOKEY (UK) LTD., CLEMENT, DAVID, ALAN, MCMURRAY, ALAN
Application year: 1994
Main classification: B23C3
IPC codes: B23C3